The RFID (Radio Frequency Identification) system is attracting attention and, for example, is being introduced in the field of distribution and the like. The RFID system includes an IC chip and an antenna, and is constituted by an RF tag (also referred to as a wireless tag or an RFID tag) attached to each product and an RF tag reader and writer (hereinafter, also simply referred to as a reader and writer) for reading information stored in a memory within the IC chip of the RF tag in a non-contact manner and writing information in the memory within the IC chip of the RF tag in a non-contact manner.
In regard to processing by the RFID system, a collective information reading process from a plurality of RF tags (hereinafter, referred to as collective reading) in regard to counting inventory in a shop or the like can be exemplified. At this time, the reader and writer radiates radio waves in a range of up to several meters, executes communication with unspecified RF tags each of which is attached to each of a plurality of commercial products, and collectively reads the information stored in the respective RF tags. In addition, in regard to other processing by the RFID system, it is possible to exemplify reading and writing processes with respect to one or a plurality of specific RF tags (hereinafter, both of which are referred to as selective reading and selective writing, respectively, and are together referred to as selective communication). At this time, the reader and writer selectively reads information from specific RF tags or selectively writes information in the RF tags.
Here, there are cases where selective writing process or the like is performed in the circumstances of a shop or the like, in which there are a number of commercial products with the RF tags attached. In such circumstances, information may be written to an RF tag which is different from an RF tag to which a user desires to write the information, as a result of the communication with nearby RF tags by mistake. Accordingly, in the conventional technique, depending on the operation, the user was required to use both a reader and writer for collective reading and a reader and writer for selective communication, which has a smaller radio wave transmission output and has a narrower range of directionality than that of the reader and writer for collective reading. In addition, when performing selective communication, the user was required to perform an action such as keeping RF tags which were not communication targets away from the vicinity of the antenna device of the reader and writer.